共查询到20条相似文献,搜索用时 15 毫秒
1.
The entropy squeezing properties for a two-level
atom interacting with a two-mode field via two different competing transitions
are investigated from a quantum information point of view. The influences
of the initial state of the system and the relative coupling strength between the atom and the field
on the atomic information entropy squeezing are discussed. Our results show that
the squeezed direction and the frequency of the information entropy squeezing
can be controlled by choosing the phase of the atom dipole and the relative competing
strength of atom-field, respectively.
We find that, under the same condition, no atomic variance squeezing is predicted from the
HUR while optimal entropy squeezing is obtained from the EUR, so the quantum information
entropy is a remarkable precision measure for the atomic squeezing
in the considered system. 相似文献
2.
电路量子电动力学的实验实现了光与人造原子的超强耦合相互作用, 相互作用强度与光场频率在同一个数量级.在超强耦合区域, 著名的旋波近似失效, 因此系统的动力学必须用含有反旋波项的Rabi模型描述.本文研究Rabi模型中的光场压缩.数值模拟结果发现, 光场压缩不是随耦合强度线性增加, 而是在合适的超强区域获得最大值.同时, 我们还发现, 较小的反旋波项有助于提高光场压缩.所得结果有利于实验上在超强区域中制备所需的压缩态.
关键词:
Rabi模型
超强耦合
光场压缩 相似文献
3.
Cui-Xia Wang Xiong Ding Guo-Qiang Huang Cui-Lan Luo 《International Journal of Theoretical Physics》2016,55(6):2931-2935
We investigate quantum entanglement in a generic-spin model with spin squeezing criterions based on squeezing inequalities. By analytically and numerically calculating the squeezing criterions, we show that the system is always entangled except at some special times and the stronger entanglement may be achieved by decreasing the coupling strength and increasing the number of particles. 相似文献
4.
5.
We theoretically investigate the multistable behavior of a hybrid optomechanical system,in which a charged mechanical resonator is coupled via Coulomb interaction to an optomechanical cavity containing an optical parametric amplifier(OPA).It is shown that the multistable behavior of the mean intracavity photon number can be controlled flexibly by adjusting the nonlinear gain parameter of the OPA,the phase of the field pumping the OPA,the power and frequency of the field driving the cavity,and the Coulomb coupling strength between the two charged mechanical resonators.In particular,the increase of the nonlinear gain parameter can result in a transition from testability to Instability.Moreover,the effect of the Coulomb coupling strength on the bistable behavior of the steady-state positions of the two mechanical resonators is discussed. 相似文献
6.
7.
N. Galler H. Ditlbacher A. Hohenau A. Leitner F. R. Aussenegg J. R. Krenn 《Applied physics. B, Lasers and optics》2011,104(4):931-934
We propose an optical attenuator concept based on a polymer waveguide coupled to an elastomer thin film. The thickness of
the elastomer layer can be controlled by Coulomb force-induced squeezing in a capacitor geometry. Thereby resonant coupling
between the light modes in the waveguide and the elastomer layer is achieved. We predict close to 100% modulation contrast
and about 40% transmission for an about 200 μm long device. In addition, we demonstrate experimentally a proof-of-principle
of the attenuator device. 相似文献
8.
Entropy squeezing for a two-level atom in two-mode Raman coupled model with intrinsic decoherence 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
In this paper, we investigate the entropy squeezing for a two-level
atom interacting with two quantized fields through Raman coupling.
We obtain the dynamical evolution of the total system under the
influence of intrinsic decoherence when the two quantized fields are
prepared in a two-mode squeezing vacuum state initially. The effects
of the field squeezing factor, the two-level atomic transition
frequency, the second field frequency and the intrinsic decoherence
on the entropy squeezing are discussed. Without intrinsic
decoherence, the increase of field squeezing factor can break the
entropy squeezing. The two-level atomic transition frequency changes
only the period of oscillation but not the strength of entropy
squeezing. The influence of the second field frequency is
complicated. With the intrinsic decoherence taken into
consideration, the results show that the stronger the intrinsic
decoherence is, the more quickly the entropy squeezing will
disappear. The increase of the atomic transition frequency can
hasten the disappearance of entropy squeezing. 相似文献
9.
Xiao-Fang Ouyang 《International Journal of Theoretical Physics》2014,53(3):754-758
We investigate spin squeezing in optomechanical system. We first derive the mean spin direction, the optimally squeezed angle and then calculate the spin squeezing parameter, which is independent of the frequency of the cavity field. The lager coupling strength more rapidly generates spin squeezed state, but the corresponding spin squeezed state maintains shorter time interval. 相似文献
10.
Enhancing stationary entanglement between two optomechanical oscillators by Coulomb interaction with Kerr medium
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Tian-Le Yang 《中国物理 B》2021,30(12):124201-124201
We theoretically study the stationary entanglement of two charged nanomechanical oscillators coupling via Coulomb interaction in an optomechanical system with an additional Kerr medium. We show that the degree of entanglement between two nanomechanical oscillators is suppressed by Kerr interaction due to photon blockade and enhanced by Coulomb coupling strength. We also show other parameters for adjusting and obtaining entanglement, such as the driving power and the frequencies of the two oscillators, and the entanglement is robust against temperature. Our study proves a way for adjusting stationary entanglement between two optomechanical oscillators by Coulomb interaction and Kerr medium. 相似文献
11.
12.
运用全量子理论并结合数值计算方法,研究了Kerr介质腔中处于Bell态的两个全同二能级纠缠原子与双模纠缠相干光场相互作用系统的原子偶极压缩特性.讨论了双原子体系的初态、光场的平均光子数、双模纠缠相干光场的纠缠程度以及Kerr介质与双模光场的耦合强度对原子偶极压缩特性的影响.结果表明:双原子体系的初态为|β11>时,不会出现偶极压缩效应;初态为|β00>,|β01>或|β10>时在一定条件下可能出现原子压缩效应,且此时原子压缩的特性与Kerr介质与双模光场的耦合强度、初始光场的平均光子数、双模纠缠相干光场的纠缠程度有关.
关键词:
量子光学
Bell态
双模纠缠相干光场
Kerr介质 相似文献
13.
We propose a scheme to coherently control spin squeezing of atomic Bose-Einstein condensate (BEC) via the technique of electromagnetically induced transparency (EIT). We study quantum dynamics of the mean spin vector and spin squeezing. It is shown that the mean spin vector and spin squeezing of the BEC can be controlled and manipulated by adjusting the external coupling fields or/and internal nonlinear interactions of the BEC. It is indicated that the spin squeezing can be generated rapidly in the dynamical process and maintained in a long time interval. It is found that a larger effective Rabi coupling between atoms and lasers can produce a stronger spin squeezing, and the squeezing can maintain a longer time interval. 相似文献
14.
We investigate quantum coherence and spin squeezing in optomechanical system. We first determine the mean spin direction, the optimally squeezed angle and then calculate the first-order temporal correlation function, the squeezing parameter, which are independent of the frequency of the cavity field. The lager coupling strength more rapidly generates spin squeezed state, but the corresponding spin squeezed state maintains shorter time interval. 相似文献
15.
The cavity magnomechanical system has become a promising platform for preparing macroscopic quantum states. In this work, a scheme for generating the steady-state quadrature squeezing of the magnon and phonon modes in a cavity magnomechanical system is presented. This scheme uses a degenerate microwave parametric amplifier (PA) inside the microwave cavity. It is found that the squeezing of the cavity mode produced by the PA can be transferred to the magnon mode due to the cavity-magnon beamsplitter-like interaction, and the squeezing of the magnon mode can be further transferred to the phonon mode due to the magnon-phonon beamsplitter-like interaction induced by driving the magnon mode with a red-detuned microwave field. The effects of the parametric gain and phase of the PA, the magnon-cavity coupling strength, the power of the magnon drive, and the temperature of the environment on the squeezing of the magnon and phonon modes have been evaluated. The results show that the squeezing of the magnon and phonon modes is robust against the temperature of the environment. 相似文献
16.
An experimentally feasible strong coupling system between a spin ensemble and a superconducting qubit is studied. The coupling strength can be exponentially enhanced by applying the squeezing transformations to the system. By means of the two spin ensembles commonly coupled to a superconducting qubit, a set of universal nonadiabatic holonomic single‐qubit quantum gates can be realized in a decoherence‐free subspace. Furthermore, this proposal is robust with respect to decay of the system parameters, and it is experimentally feasible with currently available technology. 相似文献
17.
We consider the quantum entanglement such as spin squeezing and the reciprocal of the mean quantum Fisher information per particle(RMQFIP) resulted from the phonon-induced spin-spin interactions in diamond nanoresonator. The entangled state can be generated by adjusting the near-resonant coupling and the single phonon coupling strength and the better entanglement and a longer entangled time interval can be achieved by increasing the number of charged nitrogen-vacancy (NV) centers. 相似文献
18.
Phase-modulated quadrature squeezing in two coupled cavities containing a two-level system
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
《中国物理 B》2020,(5)
The phase-modulated quadrature squeezing in the system that composed of two coupled cavities interacting with a two-level atom is investigated. The variances of the amplitude and phase quadrature of the output field are calculated.It turns out that the squeezing behaviors of the output field can be obviously modified due to the phase difference of the coupling strengths between the atom and the two cavities. The squeezing in one quadrature(i.e., phase quadrature) can be transferred into another(i.e., amplitude quadrature), or the quadrature squeezing located at the low-frequency region can be transferred into the high-frequency region by modulating the relative phase of the coupling strengths. Furthermore, the effects of the decay mismatch between the two cavities and the coupling mismatch between the atom and the cavities on the quadrature squeezing have been discussed. The results show that both the decay mismatch and the coupling mismatch play a positive role in generating better quadrature squeezing. 相似文献
19.
Properties of field quantum entropy evolution in the Jaynes--Cummings model with initial squeezed coherent states field
下载免费PDF全文
![点击此处可从《中国物理》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The properties of the field quantum entropy evolution in a system of
a single-mode squeezed coherent state field interacting with a
two-level atom is studied by utilizing the complete quantum theory,
and we focus our attention on the discussion of the influences of
field squeezing parameter $\gamma $, atomic distribution angle
$\theta $ and coupling strength $g$ between the field and the atom
on the properties of the evolution of field quantum entropy. The
results obtained from numerical calculation indicate that the
amplitude of oscillation of field quantum entropy evolution
decreases with the increasing of squeezing parameter $\gamma $, and
that both atomic distribution angle $\theta $ and coupling strength
$g$ between the field and the atom can influence the periodicity of
field quantum entropy evolution. 相似文献
20.
Murillo MS 《Physical review letters》2001,87(11):115003
We investigate the possibility of forming a strongly coupled ion plasma from a cold atomic gas. We show that rapid ion heating occurs as correlations develop from the initial disordered configuration. This heating severely reduces the Coulomb coupling of the final configuration, although the final Coulomb coupling can be maximized by introducing order into the initial atomic gas. We show that such order can be introduced into the initial state by employing a degenerate Fermi gas whereby the Pauli hole mimics the Coulomb hole. The corresponding initial state correlations can enhance the Coulomb coupling in the final state by orders of magnitude. 相似文献